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LABORATORY PROFICIENCY TESTING PROGRAM - REPORT NO 17 METAL EXAMINATION

NCJ Number
47538
Author(s)
ANON
Date Published
1977
Length
22 pages
Annotation
TEST ANALYSES OF 3 METAL SAMPLES PERFORMED BY 68 FORENSIC LABORATORIES ARE DOCUMENTED IN CHARTS AND TABLES.
Abstract
THE REPORT IS ONE OF A SERIES OF LABORATORY PROFICIENCY TEST DOCUMENTS. EACH LABORATORY WAS SENT THREE METAL SAMPLES REPRESENTING EVIDENCE COLLECTED IN CONNECTION WITH A CRIMINAL CASE. THE LABORATORIES WERE TO DETERMINE WHETHER ANY OF THE SAMPLES COULD HAVE COME FROM THE SAME SOURCE AND TO INDICATE THEIR METHODS OF ANALYSIS. IN REALITY, SAMPLES B AND C WERE THE SAME METAL (A TYPE OF STEEL). OF THE RESPONDING LABORATORIES, 62 (93.9 PERCENT) RESPONDED THAT A AND B WERE NOT THE SAME, 61 (92.4 PERCENT) RESPONDED THAT A AND C WERE NOT THE SAME, AND 41 (77.3 PERCENT) RESPONDED THAT B AND C WERE THE SAME. DETAILS OF THE LABORATORIES' METHODS AND FINDINGS -- INCLUDING A BREAKDOWN OF RESPONSES FROM INDIVIDUAL LABORATORIES -- ARE PRESENTED IN TABLES. SURVEY METHODS ARE EXPLAINED, AND A COPY OF THE STUDY INSTRUMENT IS PROVIDED. PROFICIENCY TESTS INVOLVING OTHER FORMS OF PHYSICAL EVIDENCE ARE REPORTED IN NCJ-47522-47537 AND 47539-47542. (LKM)